Authentication

When making requests for transcoding, you must include an authentication token in the Authorization header. This token is a security measure that ensures only authorized requests are processed.

Important: The token incorporates your AccessKey and is cryptographically signed using your AccessKey Secret. Ensure you have obtained your unique AccessKey and AccessKey Secret before proceeding.

Token Format

The authentication token follows this format:

Token = [AccessKey]:[EncodeSign]

Where:

• AccessKey: Your unique public identifier.
• EncodeSign: A URL-safe Base64 encoded HMAC-SHA1 signature.

The process of generating the authentication token involves the following steps:

1. Generate the EncodeSign
2. Construct the Token

Let’s delve into each step.

Step 1: Generate EncodeSign

The EncodeSign is generated by applying a series of transformations to StringToSign and AccessKey Secret.

EncodeSign = Urlsafe_base64_encode(HMAC_SHA1(StringToSign,AccessKey Secret))

The process is outlined below:

Formulate StringToSign

The StringToSign is constructed based on the type of request. For media processing requests, it adheres to the following format:

StringToSign = '/fops' + '\n' + [Request Body]

• /fops: A fixed string indicating the operation.
• \n: A newline character.
• [Request Body]: The body of your transcoding request.

If your Request Body is: bucket=[bucket_name]key=[file_to_process]fops=[processing_operations], your StringToSign will be:

/fops\nbucket=[bucket_name]key=[file_to_process]fops=[processing_operations]

Note: The example Request Body shown here is the original string for clarity. In your actual request, you might be using the base64 encoded string.

Compute the Signature

Once you have formulated the StringToSign, use your AccessKey Secret as the key to compute the HMAC-SHA1 signature:

Signature = HMAC_SHA1(StringToSign, AccessKey Secret)

You can get your AccessKey and AccessKey Secret by navigating to Basic Information > Account Management > API Information Management > AccessKey Management.

For implementation details and examples of the HMAC-SHA1 algorithm, you can refer to:

• HMAC on Wikipedia
• CDNetworks Example Code for HMAC-SHA1

Base64 Encode the Signature

Finally, apply URL-safe Base64 encoding to the computed Signature to obtain the EncodeSign:

EncodeSign = Urlsafe_base64_encode(Signature)

Step 2: Create the Token

After generating the EncodeSign and obtaining your AccessKey, combine them in the specified format to create your authentication token:

Token = [AccessKey]:[encodeSign]

This token must be included in the Authorization header of your transcoding requests.

Examples

For practical demonstrations of token generation, including executable code examples, please refer to:

Authentication Token Generation Examples

These examples can help you understand the implementation details and quickly integrate token generation into your applications.